The invention relates generally to a device for housing optical fibers split from a ribbon fiber or a buffer tube.
In fiber optic communications networks, many optical fibers are used to transmit signals throughout the network. Because optical fibers are small, multiple optical fibers are often routed together in groups of fibers that are connected or bundled together. One arrangement of multiple optical fibers is a ribbon fiber, which is a group of optical fibers (typically 12 fibers) aligned in a single plane and held together by a film. To access or split out the individual fibers from the ribbon fiber, the film is stripped in the area in which the split is needed. The stripping of the film is usually accomplished using a solvent. The area where this ribbon fiber is split must be protected and the ribbon fiber on one side of the split and the individual fibers on the other must be strain relieved to prevent damage to the fibers.
Another type of multiple fiber arrangement is loose tube fiber, which includes a plurality of groups of fibers (typically from 2 to 12). These groups of fibers are housed in buffer tubes, which are typically made of extruded plastic. To access or split out the individual fibers, the buffer tubing is sheathed in the area access is needed without damaging the fibers. The area where the buffer tube is opened must be protected and strain relieved to prevent damage to the optical fibers.
Devices currently exist for housing optical fiber splits. One such device houses the split of a ribbon fiber. Another device houses the split of loose tube fiber. However, no single device exists for housing the splits from both a ribbon fiber and loose tube fiber. Therefore, there is a need in the art for a single device that houses splits for both ribbon fiber and loose tube fiber.
Additionally, current devices utilize a single cover for covering the device that houses the fiber splits. However, when the cover is removed to reenter the device, the strain relief area is disturbed. This is undesirable because disturbing the strain relief area during reentry subjects the optical fibers to damage. Therefore, there is a need in the art for a device that allows the local area in which a fiber split is housed to be accessed without disturbing the strain relief area.
The present invention is a device that alternatively houses a split of either a ribbon fiber or a buffer tube into individual fibers or bundles of fibers. The device includes a base that has a split area and a strain relief area, which includes a cavity.
For a ribbon fiber, strain relief is provided by placing two bumpers, preferably made of rubber, on opposite sides of the ribbon fiber in the cavity. The walls of the cavity prevent movement of the bumpers and ribbon fiber in two directions. Movement of the bumpers and ribbon fiber in a third direction is prevented by a cavity cover that is removably connected to the base over the cavity. Preferably, the portions of the rubber bumpers that contact the ribbon fiber are coated with an adhesive, which prevents movement of the ribbon fiber from between the bumpers.
The cavity cover has tabs that mate with receptacles in the base with an interference fit so that the cover holds the bumpers in the cavity. A split area cover covers the remainder of the base to protect the split fibers from dust and handling. Both the cavity cover and the split area cover can be independently connected to and removed from the base. In this manner, the split area cover can be removed to access to the split fibers without removing the cavity cover.
The ribbon fiber can also be placed between a strain relief member before being placed between the bumpers in the cavity. The strain relief member has two similarly shaped portions that are folded onto one another with the ribbon fiber therebetween. The portions are folded at the connection point such that the fold runs in the same direction as the straight section of the member. The surface of each portion that is folded onto each other is preferably coated with an adhesive to better retain the ribbon fiber within the strain relief member. The strain relief member preferably has an extended middle section dimensioned to fit within the cavity to prevent movement of the strain relief member from the cavity.
The same device can also be used to alternatively provide strain relief for a buffer tube. The buffer tube is tied down within the cavity to provide strain relief to the buffer tube. The buffer tube is tied down by routing a tie wrap or any other suitable retaining strap through at least one aperture in the bottom of the cavity. Preferably, there are two apertures spaced apart in the bottom of the cavity, and the tie wrap is routed into the cavity through one aperture, around the buffer tube, and then out of the cavity through the other aperture.